Thread: oil blowing out at high speeds

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If your pcv is working correctly,your other hose should be letting fresh air into the engine. Changing cams can giveyou more cylinder filling,increasing the chance of blowby pressurizing the crankcase. You could test for this by hooking a vacuum/fuel pump pressure gauge to your breather cap and going for a ride. How much manifold vacuum did you lose from the cam swap? Hank

Does the hose on the right side go into the bottom of the breather? If so wont your pvc line on the left, and the hose on the right be fighting against each other. And you cant have a channel of air flowing through that way can you? Ive always thought one had to be vented to let air in and the other was set to a vacume port to draw the air through. I dont know I am just asking.

Hank I have a manifold pressure gauge always hook up to my engine and I run 15 lbs. at idle and 25 a full throttle.

Mooneye 777 the pcv valve vents the crankcase of excessive pressure into intake manifold or intake system. What I'm doing is taking the blowbye that the pcv valve is not taking all of and using the vacuum from the carb or intake to drawn the fumes into the carb and burn it off. I really don't know if this is harming the engine or not but there is no more blowby at high speeds, just oil blowing past the dipstick or oil cap on the valve cover. Maybe to much pressure is causing this but it just happened when changing cams, and the cam is not a aggressive one.

Pat. I'm using the highest breather cap I can find. I even made my own that was 4 " tall, but it still didn't work. The cam specs are 262-270 adv. dur Int/Exh. 218/225 Dur.050 Int./Exh. Lift int./exh. .462-.469 lobe seperation 110 degree.